Recently a monk wrote about the 5, 8 and 10 precepts… and telling people to "feel free to share". I hope not too many people will do so.

After listing them, and making explicit the differences between the three lists of precepts, he started his conclusion with something that made some sense, but was nonetheless seriously tainted:
« We could say that one can be defined [as a lay buddhist, a serious buddhist or a novice monk] by the rules they follow. So it is important [for monks] to not use money. If you do, you are only [sic] following the rules of a serious Buddhist lay person. There is only one rule that separates the serious lay practitioner and the novice monk and that is using money. »
This is heavily tainted by conceit, with the view that monks are automatically 'superior' to serious lay people, regardless of the facts that one doesn't 'attain' anything automatically by becoming a monk, and that lay people who support the monks may well be stream-enterers, once-returners or non-returners who generously offer their support for others to indeed attain the same, in a supportive environment… Typical self-serving institutional fallacy! It takes monasticism to believe that being a monk with no attainment is somehow better than being a lay non-returner, it also takes dismissing (not appreciating) the support received from lay people or taking it for granted / due.

Righteousness is a hindrance, so I'd call on people not to fall into righteous beliefs about who's a (self-proclaimed) "serious" buddhist and who's not. Precepts are a guidance for oneself, never to judge others (of who we don't know the karma, in particular as long as we're not free from biases, i.e. as long as we're not buddhas). The following is therefore the wrong attitude, even when applied to oneself since it presents the holy life as a competition of righteousness:
« However, if you eat after NOON, you are no longer even following the rules of a Serious Buddhist Lay Person. You are just [sic!] following the rules of a regular “run of the mill” Buddhist Lay person. »
Sure, the Buddha used such "run of the mill" expressions, but taking them out of context is what's ignorant here. What's an expedient means in relation to an audience of monastics is not to be spread to an audience of "general public" as a generic, contextless truth!

« The Buddha said, “In the same way, Rahula, when anyone feels no shame in telling a deliberate lie, there is no evil, I tell you, he will not do.” (MN 61). Therefore, although breaking both eating and money rules are bad, we can say that eating after NOON is worse because the monk is not even following the morality of a serious Lay Buddhist practitioner. He is only [sic!] following the precepts of a “run of the mill” lay Buddhist person. »
Following precepts is a matter of intention, and of cultivation: trying again and again until one succeeds to reform unwholesome tendencies. This is not about judging people! This is not even about breaching, or not breaching: that's why there are penances defined, after a breach, to move on because everybody has breached these rules countless times over countless lives! The event of a breach is not what it's about, it's about the lessons you draw, it's about the renewed intention that arises… The monk working hard to reform himself, who keeps trying with perseverance after every misstep, is more meritorious (in line with « right effort ») than the monk who easily respects a precept simply because this particular temptation is not part of his conditioning.
And if a monk is on the path then, when he sees someone else breach a precept, he should encourage this person to be mindful of it and to amend the situation, but he should also enquire into his own failings, at the very least the failing to support the person who just breached a precept! The monk should ask himself how he could support others better, and take responsibility for not having done so enough (or not in the appropriate way)! Sure, admonition can be appropriate at times, but one has to be extremely clear as to both the goal and the execution along the way…

Now, if we're to play with quotes, then the Buddha said «It's a cause of growth in the Dhamma and Vinaya of the noble ones when, seeing a transgression as such, one makes amends in accordance with the Dhamma and exercises restraint in the future.
» — Samaññaphala sutta (DN 2)

He also said: «These two are fools. Which two? The one who doesn't see his/her transgression as a transgression, and the one who doesn't rightfully pardon another who has confessed his/her transgression. These two are fools.These two are wise. Which two? The one who sees his/her transgression as a transgression, and the one who rightfully pardons another who has confessed his/her transgression. These two are wise.
» — Bala-pandita sutta (AN 2.21)

But this monk wrote what amounts to the opposite of « right speech » in my view (not the first time I disagree with this monk), and therefore I think this doesn't qualify at all as wholesome "admonition" but it simply is conceited insults:
« About the classes of offenses. Lying is simply “only a confession classed rule (Pācittiyā).” Do you agree that a monk who lies is below the morality of a monk who eats after NOON and below a monk who uses money? Of course, because he is no longer classed as following the rules of even a simple Buddhist lay person. He is sub-humane. »

First, the offences are already classified, and a Theravādin is not in a position to say that rules should be amended… if it's a 'minor' offence, it is a 'minor' offence, end of the vinaya conversation! Handling gold and silver? Nissaggiya Pācittiya. Lying? Mere Pācittiya These are clearly not in the same category and lying is minor compared to handling money.

Second, to invert the hierarchy by fallacious logic here is an example of a classic error of "priority inversion", or not keeping the eyes on the ball. If such logic was correct, I could use the tiniest of offences among the 250 or so rules that a full-fledged monk should follow, one of these offences that a monk doesn't even have to disclose to others (he only has to admit it to himself), and I could consider that the tiniest breach would make the "senior monk" fall back to "novice monk" (a level at which the rule breached doesn't exist)… even though the vinaya is explicit that such a breach doesn't matter as long as one takes notice and tries again, since a sekhiya rule exist solely to help the training of "24/7 mindfulness"! So, no, breaching a rule does not make anyone fall down to a level where the rule doesn't apply! The logic is the other way round: merely trying to follow the rule, rather than not trying, is meritorious. It's better to succeed than to fail, but it's also better to try than not to try!

And, finally, wow, how judgemental can one get? Like thinking only buddhists (who took precepts) are 'humane'? Like all other religions or atheists are animals? Even for the most 'missionary', this is breaching « right speech » since such words would repel people rather than motivate them to enquire about Buddhism! This is exactly what's wrong in Myanmar (or Burma) at the moment, and how the genocide of Rohingya muslims is justified… To endorse any "sub-humane" narrative is clearly delusional, lacking compassion, and being blind to the damage (possibly death!) that one's words will lead to.

Let's get back to the Samaññaphala sutta (DN 2):
«Abandoning false speech, he abstains from false speech. He speaks the truth, holds to the truth, is firm [so admonition might be on the menu, fair enough], reliable, no deceiver of the world. This, too, is part ["part", not the whole: no excuse to ignore the rest!] of his virtue.

Abandoning divisive speech he abstains from divisive speech. What he has heard here he does not tell there to break those people apart from these people here. What he has heard there he does not tell here to break these people apart from those people there. Thus reconciling those who have broken apart or cementing those who are united, he loves concord, delights in concord, enjoys concord, speaks things that create concord. This, too, is part of his virtue.

Abandoning abusive speech, he abstains from abusive speech. He speaks words that are soothing to the ear, that are affectionate, that go to the heart, that are polite, appealing and pleasing to people at large [well-executed admonition is considered "pleasing" in the long-term…]. This, too, is part of his virtue.

Abandoning idle chatter, he abstains from idle chatter. He speaks in season, speaks what is factual, what is in accordance with the goal, the Dhamma, and the Vinaya [without cherry-picking what's self-serving, without conceit] He speaks words worth treasuring, seasonable, reasonable, circumscribed, connected with the goal. This, too, is part of his virtue.
»

I'm not against admonitions, or shaking up comfortable certainties, excuses or narratives. It has to be kept to a minimum, in order to remain effective (no permanent rant is taken seriously…), but even if compassion is 99% 'smiling', it's not a caricatural 100%: cf. the notion of wrathful deities or some discourses of the Buddha! So I have no difficulty with admonitions as an expedient means.

Yet, it's very important to contextualise! Co-dependent arising, anyone?

It's also important to aim for bringing people into the fold: it's about guiding them to do better, not locking them outside "the meritorious ones". The path is not about a social status or monasticism, the Buddha indicated clearly that a 'Brahmin' is not so by social norms nor good karma (not even buddhist monastic norms nor buddhist karma) but by how one acts: « By birth one is not an outcaste, By birth one is not a Brahmin; By deeds alone one is an outcaste, By deeds alone one is a Brahmin »!

Admonitions should not end with calling 'others' sub-humane but with « the good news is that, if you recognised yourself in what was criticised, then you can change! And this is what it would take: …… »

It's about change, about responsibility, about empowerment, about Liberation. And responsibility and empowerment are about consequences, not mere training rules… It is about rejecting self-identification ("this is what I do, what people-like-me do"), avoiding self-based fallacies ("this person is good, that person is bad, this cannot change"), it's about discerning wholesome and unwholesome behaviours / conducts / "deeds", in the context at hand.